HISTOPLASMA DNA PCR TEST

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Histoplasma capsulatum (also known as Ajellomyces capsulatum) is a dimorphic fungus which is the causative agent of Histoplasmosis, which primarily affects the lungs. Most infections are asymptomatic, but the acute phase may present mild respiratory symptoms. Chronic histoplasmosis may progress to disseminated disease, which can be fatal, especially in immunocompromised individuals (e.g., HIV patients), though cases in healthy individuals have also been reported. Central nervous system (CNS) involvement may occur with or without disseminated disease and can present as meningitis or other neurologic manifestations; therefore, detection of Histoplasma DNA in cerebrospinal fluid (CSF) may support evaluation for CNS histoplasmosis when interpreted in conjunction with clinical findings and other laboratory results. Histoplasmosis is endemic to parts of the Americas, Asia, and Africa, but can occur elsewhere. The gold standard for diagnosis of histoplasmosis remains isolation of the organisms in culture. Although sensitive, recovery in culture and subsequent identification may require days to weeks. This polymerase chain reaction assay can provide rapid and specific detection and differentiation of Histoplasma capsulatum directly from clinical specimens.

Qualitative Real-Time PCR (Polymerase Chain Reaction)

Specimens positive for Paracoccidioides brasiliensis, Aspergillus flavus, Aspergillus nidulans, and Aspergillus niger may cross react and test positive. When tested in cultures of 10⁸ – 10⁹ organisms/mL, cross-reactions occurred with Paracoccidioides brasiliensis, Aspergillus flavus, Aspergillus nidulans, and Aspergillus niger.

Fluconazole may interfere with assay sensitivity. When tested with Fluconazole at 7.0 ug/ mL in CSF specimens, interference occurred that lead to false negative test results.

BAL, CSF, tracheal aspirate*, or bronchial wash* in a sterile leak-proof container.

* Reported with a rare specimen comment applied.

BAL, CSF, tracheal aspirate*, or bronchial wash* = 0.5 mL

* Reported with a rare specimen comment applied.

BAL

• Room Temperature: 30 days
• Refrigerated: 30 days
• Frozen: 30 days

CSF

• Refrigerated: 5 days
• Frozen: 30 days

• Sputum and all other non-respiratory samples.
• Two unique patient identifiers are required on the specimen container.
• Specimens with particulate matter or viscosity that would not allow the specimen to be pipetted will be rejected.
• Grossly bloody CSF specimens will be rejected.

• Refrigerated
• Frozen

Samples may be shipped on dry ice or frozen ice packs

Same Day

Not detected

PCR testing should be done in conjunction with appropriate microbiology, antigen, and/or antibody testing. A positive PCR result indicates the DNA was detected in the sample and that organism could be the cause of disease.  Some organisms (molds and yeasts) can be commensals (or colonizers) and found in non-sterile locations such as the respiratory, GI, and urinary systems – without causing disease.  A negative result indicates DNA was not detected in the sample but does not rule-out that organism as the cause of disease. All results should be interpreted considering the full clinical picture.

This test was developed, and its analytical performance characteristics were determined by MiraVista Diagnostics. It has not been cleared or approved by the FDA; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

• Bronchoalveolar Lavage (BAL)
• Cerebral Spinal Fluid (CSF)